• Title/Summary/Keyword: Vibrational enhancement

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Vibrational enhancement of evolutionary monochromatic neutron transport

  • Nassar H.S. Haidar
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2563-2569
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    • 2024
  • The monochromatic hyperbolic neutron density wave is conceived as a Rayleigh-like wave with mixed transverse and longitudinal components. It is proved for the first time that the absolute ratio of the longitudinal to transverse interfering components, varies, with increasing the frequency of this wave, from zero to 1. Such a limited variation is to be coined as vibrational enhancement of evolutionary one-speed neutron transport.

Tensor Components in Three Pulse Vibrational Echoes of a Rigid Dipeptide

  • Dreyer, Jens;Moran, Andrew M.;Mukamel, Shaul
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1091-1096
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    • 2003
  • The effects of different polarization conditions on vibrational echo signals are systematically explored for the rigid cyclic dipeptide 2,5-diazabicyclo[2,2,2]octane-3,6-dione. An anharmonic vibrational Hamiltonian is constructed by computing energy derivatives to fourth order using density functional theory. Molecular frame transition dipole orientations are then used to calculate polarization dependent orientational factors corresponding to various Liouville space pathways. Enhancement and elimination of specific peaks in twodimensional correlation plots is accomplished by identifying appropriate pulse configurations.

Fluorescence Enhancement of Ethidium Bromide by DNA Bases and Nucleosides

  • Pyun, Chong-Hong;Park, Su-Moon
    • Bulletin of the Korean Chemical Society
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    • v.10 no.2
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    • pp.142-147
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    • 1989
  • Fluorescence enhancements of ethidium bromide (EB) by solution species of low molecular weights such as DNA base molecules and nucleosides in water are reported. The degree of enhancements was determined by intensity as well as lifetime measurements for EB fluorescence. Experiments including solvent effects on absorbance and fluorescence spectra of EB, effects of protonation on the EB absorbance spectrum, and determination of equilibrium constants for EB-DNA bases have been performed to help explain the fluorescence enhancement. The results suggest that the excited state stabilization in the hydrophobic environment, the loss of torsional/vibrational energy of amino groups, and the change in the electronic transition characteristics are all responsible for the fluorescence enhancement.

ESPI Simulation for the Vibration Modes of the Thin Right-Angled Plate (얇은 직각판의 진동 모드에 대한 ESPI 시뮬레이션)

  • 장순석
    • Journal of KSNVE
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    • v.9 no.3
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    • pp.509-516
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    • 1999
  • The ESPI (Electronic Speckle Pattern Interferometry) algorithm has been simulated to calculate vibrational modes of a thin right-angled STS304 plate. The phase transformation of the reference wave of the ESPI is carried out only one time during vibration in order to clarify ESPI speckle patterns. Two dimensional vibrational modes are calculated from one ESPI pattern before vibration onset and two ESPI patterns during vibrations but with and without the phase transformation. The ESPI harmonic results are compared with those derived from the finite element method (FEM), and they agree very well. Additionally a phase unwrapping algorithm has been newly developed to derive a displacement map from an ESPI phase map.

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SERS Study of Quinoline Using the Silver Surface (Silver Surface를 이용한 Quinoline의 SERS 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.3
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    • pp.101-104
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    • 2011
  • In this study, the experiments for surface enhancement of silver surfaces were done, where we checked the characteristics of silver surfaces made by Tollen's method. The surface enhancement of Quinoline was analyzed by three kind of silver mirror substrates. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. Finally, we deduced that the adsorption orientation of quinoline was little tilted flat to the silver mirror surfaces by using of the surface selection rules.

Study on Surface Enhanced Raman Scattering of Methyl Orange According to the Characteristics of Silver Surface (Silver Surface의 특성에 따른 Methyl Orange의 표면증강라만스펙트럼에 관한 연구)

  • Lee, Chul-Jae
    • Journal of the Korean Society of Industry Convergence
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    • v.21 no.3
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    • pp.103-108
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    • 2018
  • In this study, the experiments for surface enhancement of silver mirror substrates were done, where we checked the characteristics of silver surface made by Tollen's method. The surface enhancement of Methyl orange was analyzed by silver surfaces. We observed the Surface Enhanced Raman Spectra of Methyl orange. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. We deduced that the adsorption orientation of Methyl orange was little tilted parallel to the silver surfaces by using of the surface selection rules.

SERS Study of Bromothymol Blue Using the Silver Mirror substrate (Silver Mirror Substrate를 이용한 Bromothymol Blue의 SERS 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.2
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    • pp.43-47
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    • 2012
  • In this study, the experiments for surface enhancement of silver mirror substrate were done, where we checked the characteristics of silver mirror substrate made by Tollen's method. The surface enhancement of Bromothymol blue was analyzed by three kind of silver mirror substrates. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. Finally, we deduced that the adsorption orientation of bromothymol blue was little tilted flat to the silver mirror surfaces by using of the surface selection rules.

SERS Study of Eriochrome Black T Using the Silver Mirror Substrates (Silver Mirror Substrate를 이용한 Eriochrome Black T의 SERS 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.1
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    • pp.23-27
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    • 2011
  • In this study, the experiments for surface enhancement of silver mirror substrates were done, where we checked the characteristics of silver mirror substrate made by Tollen's method. The surface enhancement of Eriochrome Black T(EBT) was analyzed by silver mirror substrates. We observed the SERS spectra of EBT. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. Finally, we deduced that the adsorption orientation of EBT was little tilted perpendicular to the silver mirror surfaces by using of the surface selection rules.

SERS Study of Fluorescein Using the Silver Sol and Silver Mirror Substrates (Silver Sol과 Silver Mirror Substrate를 이용한 Fluorescein의 SERS 연구)

  • Lee, Chul-Jae;Choi, Hyun-Kuk;Jung, Maeng-Joon
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.1
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    • pp.27-32
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    • 2007
  • It has been recently reported that the SERS (Surface Enhanced Raman Scattering) effect of the silver mirror substrate made by Tollen's method is much superior to that of other substrates. In this study, the experiments for comparison of surface enhancement of silver sol and silver mirror substrates were done, where we checked the characteristics of silver mirror substrate made by Tollen's method. The surface enhancement of fluorescein was analyzed by silver sol and silver mirror substrates. We observed the SERS spectra of fluorescein. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. The surface enhancement properties for fluorescein showed that the silver mirror was more superior to sliver sol substrates. Spectra of fluorescein revealed that fluorescein was adsorbed on silver surfaces by a common oxygen atom. According to the 'surface selection rule', the vibrations in the band intensities reflect the adsorption orientation of the molecule on to the surface of SERS substrates. Therefore, we deduced that the adsorption orientation of fluorescein was little tilted perpendicular to the silver surfaces by using of the surface selection rules.

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Study on Surface Enhanced Raman Scattering of Indigo Carmine (lndigo Carmine의 표면증강라만스펙트럼에 관한 연구)

  • Lee, Chul Jae
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.2
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    • pp.155-160
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    • 2018
  • In this study, the experiments for surface enhancement of silver mirror substrates were done, where we checked the characteristics of silver surface made by Tollen's and ${\gamma}$- irradiation method. The surface enhancement of Indigo carmine was analyzed by silver mirror and silver sol surfaces. The assignments of the vibrational bands shown in SERS spectra are given based on both literature and the semi-empirical calculations at the PM3 methods. We deduced that the adsorption orientation of Indigo carmine was little tilted perpendicular to the silver surfaces by using of the surface selection rules.